1. Field of the Invention
This invention relates generally to electro-surgical unit (ESU) pencil apparatus and, more specifically, to electro-surgical pencil apparatus with a variable length electrode and smoke evacuation means, and methods therefor.
2. Description of the Related Art
In the past, when it was desired to change the length of the electrode of an ESU pencil, the electrode would be taken out, and replaced with another of different length. This created a number of problems. First, the electrodes are available only in two or three standard sizes. Thus, if the length desired by the surgeon was different from what was commercially available, then the surgeon would have to compromise and make do with the closest available size. Second, changing electrodes during an operation wastes time. Also, changing electrodes has an economic cost. And third, when an extended length electrode is used, the opening to the smoke evacuation conduit is often situated too far from the operation site to be effective. This meant that a special smoke evacuation shroud had to be used with the extended electrode, thereby further increasing the cost of the operation.
Also, in the past, it had not been possible to use an ESU pencil while operating both an argon beam coagulator and a smoke evacuation system simultaneously. This was true because the operation of the smoke evacuation system would interrupt the flow of the argon beam before it reached the site of the operation and deflect it directly into the smoke evacuation conduit.
Further, in order to evacuate the smoke from the surgical field in laparatomy when an ESU pencil handpiece without a smoke collector is used for cutting and coagulation, several methods have been used but their performances have not been satisfactory. In order to be efficient, the shroud which performs the smoke collection function must be as close as possible to the operating tip of the ESU pencil where the smoke is generated. But, this solution as embodied in prior art tended to obstruct the surgeon's view of the operation site. Accordingly, there was a need for an improved handpiece and shroud arrangement which provided for efficient smoke collection without obstructing the surgeon's view of the surgical site.
Therefore, there existed a need for an improved, reusable ESU pencil that allowed telescoping the electrode assembly containing a standard size electrode, and provided efficient smoke evacuation at all positions of the telescopic electrode assembly. Further, these improvements needed to be incorporated into an ESU-argon beam coagulator pencil.